HAVANA, Cuba (CNN) -- A Cuban television news anchor read a letter on air Monday that was reportedly written by Fidel Castro promising he would not "cling to office" or be an impediment to rising young leaders.

Ailing Cuban leader Fidel Castro as seen on Cuban television in September 2007.

"My basic duty is not to cling to office, much less to obstruct the rise of younger people, but to pass on experiences and ideas whose modest value arises from the exceptional era in which I lived," Castro's letter said, according to a CubaVision anchor.

The 81-year-old leader temporarily handed power to his younger brother Raul Castro in July 2006 after undergoing intestinal surgery. Officials say he is recovering, but they have not clarified if or when he could resume the presidency.

Castro hasn't been seen in public since his surgery, but he has appeared in numerous videos and photos in state media. He appeared in an interview aired in September commenting on such topics as global warming and the price of oil.

About 60 articles under his name have emerged. "Reflections of the Commander-in-Chief" has covered a broad range of international topics, often railing against the U.S. government.

In October, Castro accused President Bush of pushing the world to the brink of World War III and widespread famine in an essay that appeared in Cuban state media.

Castro came to power in 1959.

The release of the letter comes ahead of an electoral process that begins next month and culminates in March with the election of the Council of State, Cuba's supreme governing body. Despite ceding power to his brother, Fidel Castro remains head of the Council of State.E-mail to a friend